Detergent containing alkoxy hydroxypropylamine oxide



United States Patent US. Cl. 252137 5 Claims ABSTRACT OF THE DISCLOSURE A-lkoxy hydroxypropyl amine oxides having improved hygoscopicity and thermal stability properties are employed in detergent compositions containing alkaline builders or other synthetic detergents.

CROSS REFERENCE This is a division of copending applications Ser. No. 156,993, filed Dec. 4, 1961 and Ser. No. 324,181 filed Nov. 18, 1963 now abandoned.

This invention relates to novel tertiary amine oxide detergents and detergent compositions containing them.

In the constant improvement of organic detergent compounds, certain features have been found to be highly desirable. These features include resistance toward the ingredients imparting hardness to water, a high degree of detergency, and capacity for solubilization of hard Water soaps, such as calcium soap. Although there are a number of organic detergents which have these characteristics, detergent compounds having additional desirable characteristics find a Wider scope of application,

Thermal stability is a highly desirable property which is lacking in many detergents. Such stability is particularly desirable when detergents are subjected to heat during use or processing, as for example, in spray drying granular detergent compositions.

Another advantageous property for an organic detergent is a low degree of hygroscopicity which results in improved crystallinity. When detergent surfactants which are hygroscopic are used in bar or granular forms, desirable physical properties are impaired. Bars become soft and slimy and granules tend to cake and lose their free flowing and quick dissolving characteristics. For example, trialkylamine oxides have been found to be excellent detergent compounds but are so hygroscopic that they can be effectively used only in liquid detergent compositions.

It is the object of this invention to provide organic detergents and detergent compositions which have excellent detergency characteristics as well as improved mildness to the skin, improved thermal stability and a low degree of hygroscopicity.

It was found that these and other objects are achieved in a novel class of tertiary amine oxides having the structure set forth below and detergent compositions containing such compounds, preferably in solid form, as hereinafter more fully described.

The amine oxides of this invention are:

In the above formula R is 3-alkoxy-2-hydroxypropyl in which the alkoxy, ranges from to 18 carbon atoms in chain length; R and R are each methyl, ethyl, propyl or isopropyl. The class of compounds described above will hereinafter be referred to more simply as R R R N O.

Examples of the compounds of this invention are: N, N dimethyl 3 dodecoxy 2 hydroxypropylamine oxide; N,N diethyl 3 tetradecoxy 2 hydroxypropyl amine.

Tertiary amine oxides as a broad class of compounds are known. It was surprising to find, however, that the particular trialkylamine oxides containing particularlyplaced hydroxy groups as described above (i.e., a hydroxy group in the 2 position in R have such highly desirable properties for use as organic detergents, i.e., improved mildness, hygroscopicity and thermal stability characteristics.

It appears that only certain tertiary amine oxides have the aforementioned desirable characteristics; in these certain amine oxides, R R and R must be described above. If the alkoxy in R is longer in chain length than 18 carbon atoms or shorter in chain length than 10 carbon atoms, desired detergency is not obtained. Likewise, if R and R contain more than 3 carbon atoms, desired detergency characteristics are not obtained. The long chain 3-alkoxy-2-hydroxypropyl R radical must contain a hydroxy group in the 2 position (i.e., the second carbon atom from the nitrogen) in order to achieve improved rnildness, hygroscopicity and thermostability characteristics in accordance with this invention. When the hydroxy group in the R radical is in the 1 or alpha position, the resultant amine oxide compound has undesirable instability. The 3-alkoxy-2-hydroxypropyl R radical has the following general formula wherein R ranges from 10 to 18 carbon atoms in chain length.

The 3-alkoxy-2-hydroxypropyl compounds have reduced hygroscopicity characteristics as compared to the corresponding compound containing unsubstituted R alkyl group.

In tertiary amine oxides of this invention, R can be derived from naturally occurring fats and oils or from synthetic sources such as olefins. Mixtures of amine oxides are very suitable wherein the alkoxy in R varies in chain length in the C to C range, as for example, the alkoxy groups derived from coconut fatty alcohol (or distilled coconut fatty alcohol). Those amine oxides in which the alkoxy in R ranges from 12 to 14 carbon atoms are preferred.

The tertiary amine oxides of this invention can be prepared, in general, by oxidizing the corresponding tertiary amine. See, for example, British Patent 437,566. The corresponding tertiary amine, in general, can be prepared, 'by reacting an appropriate long chain alkyl compound with the appropriate secondary amine. The examples explain in detail such reactions. The preparation of alkyl glycidyl ethers (a source of the 3-alkoxy-2-hydroxypropyl R is described in Canadian Patent 582,404, issued Sept. 1, 1959 and US. Patent 2,989,547, issued June 20, 1961.

Compounds of this invention are useful per se as detergents and surface active agents. Desirably they are used with other materials to form detergent compositions, particularly solid form compositions as for example, bar, flakes, granular or tableted granular compositions. (The tertiary amine oxides of this invention can also be used to make liquid detergent compositions.) Such detergent compositions can contain from about 5% to about of the tertiary amine oxides of this invention and from about to about 20% of anionic organic detergents, nonionic organic detergents, water-soluble inorganic alkaline builder salts, water-soluble organic alkaline sequestrant builder salts or mixtures thereof.

Granular or flake detergents preferably contain about to about 50% of the amine oxides of this invention and from about 95% to about 50% normally solid, watersoluble inorganic alkaline builder salts, or water-soluble organic alkaline sequestrant builder salts. Bar formulations contain about 5% to about 50% of the amine oxides of this invention when used with anionic detergents, such as a soap base, and, if desired, alkaline inorganic or organic builders or inert fillers. Bar formulations can contain about 40% to about 80% of the amine oxides of this invention as the only detergent component, if desired, and the balance inert fillers or builders.

Anionic organic detergents used alone or in admixture include both the soap and on-soap detergents. Examples of suitable soaps are the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids (C C Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap. Examples of anionic organic non-soap detergents are: Alkyl glyceryl ether sulfonates; alkyl sulfates; alkyl monoglyceride sulfates or sulfonates; alkyl polyethenoxy ether sulfates; acyl sarcosinates; acyl esters of isethionates; acyl N-methyl taurides; alkylbenzenesulfonates; alkyl phenol polyethenoxy sulfonates. In these compounds the alkyl and the acyl groups, respectively, contain 10 to 20 carbon atoms. They are used in the form of water-soluble salts, the sodium, potassium, ammonium and alkyolammonium salts, for example. Specific examples are: sodium lauryl sulfate; potassium N-methyl lauroyl tauride; triethanolammonium dodecylbenzenesulfonate.

The examples of nonionic organic detergents are: polyethylene oxide condensates of alkyl phenols wherein the alkyl group contains from 6 to 12 carbon atoms (e.g., 5- octylphenol) and the ethylene oxide is present in a molar ratio of ethylene oxide to alkyl phenol in the range of 10:1 to :1; condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine wherein the molecular weight of the condensation products ranges from 5,000 to 11,000; the condensation product of from about 5 to moles of ethylene oxide with one mole of a straight or branched chain aliphatic alcohol containing from 8 to 18 carbon atoms (e.g., lauryl alcohol).

Water-soluble inorganic alkaline builder salts used alone or in admixture are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates. (Ammonium or substituted ammonium salts can also be used.) Specific examples of such salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium pyrophosphate, sodium bicarbonate, potassium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium monoand di-ortho phosphate and potassium bicarbonate. Such inorganic builder salts enhance the detergency of the subject amine oxides.

Examples of water-soluble organic alkaline sequestrant builder salts used alone or in admixture are alkali metal, ammonium or substituted ammonium amino polycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium, and triethanolammonium N-(2-hydroxyethyl)nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable. Other organic alkaline sequestrant builder salts which can be used are: Hydroxyethylethylenediaminetriacetates; 2 hydroxyethyliminodiacetates; diethylenetriaminepentaacetates; 1,2-diaminocycylhexanetetraacetates. The alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as alkaline organic sequestrant builder salts (see US. Patent 2,739,- 942).

Preferred detergent compositions contain about 10% to about 30% of the tertiary amine oxides of the invention and at least an equal amount of sodium tripolyphosphate.

Desirably the amine oxides wherein the alkoxy R contains 12 to 14 carbon atoms are used in such preferred compositions.

The detergent compositions of this invention can contain any of the usual adjuvants, diluents or additives, for example, ampholytic or zwitterionic detergents, cationic detergents, perfumes, anti-tarnishing agents, anti-redeposition agents, bacteriostatic agents, dyes, fluorescers, oxygen or chlorine bleaches, suds builders, suds depressors and the like.

The following is an example which illustrates the tertiary amine oxide compositions of this invention.

EXAMPLE 1,818 grams of dodecyl glycidyl ether was charged into a two liter autoclave. Air was purged from the head space with dimethyl amine. The autoclave was then heated to 390 F. A pressure of 450 p.s.i. was obtained in the autoclave by charging dimethyl amine into the autoclave using nitrogen pressure. A dimethyl amine blead valve was adjusted during the reaction of the ether with the dimethyl amine to keep a constant pressure and temperature. After one hour, the autoclave was cooled. The resultant N,N- dimethyl 3 dodecoxy-Z-hydroxypropylamine contained about 25% dissolved dimethylamine which was stripped off at F. at 5 mm. Hg pressure. The amination reaction is represented by the following equation:

1,000 grams of this tertiary amine was mixed with 2,789.3 grams of water, heated to 180 F. and mixed with 462 grams of 25% aqueous solution of hydrogen peroxide. The mixture was vigorously agitated. The resultant mixture was aged overnight at about 170 F. to decompose excess peroxide.

The resultant N,N-dimethyl-3-dodecoxy-2-hydroxypropylamine oxide absorbed only 0.3% water after one week of storage in an open vessel at room temperature and conditions. Only 22% water was absorbed upon extreme storage conditions of 90 F. and 80% relative humidity for 7 days. This amine oxide exhibited excellent detergency and sudsing characteristics and has excellent thermal stability.

N,N-diethyl-3-tetradecoxy-Z-hydroxy-propyl amine and N,N-dimethyl(-3-hexadecoxy-2-hydroxypr0pylamine oxide can be prepared by processes similar to that described.

The tertiary amine oxides of this invention can be used in effective detergent compositions having improved hygroscopicity and thermal stability characteristics. One has the following formula:

Spray-dried granular detergent Percent N,N-dimethyl-3-dodecoxy-2-hydroxypropylamine oxide 5 Sodium dodecylbenzenesulfonate 15 Sodium tripolyphosphate 50 Sodium sulfate 15 Sodium silicate 5 Moisture 10 5 6 tergents, inorganic alkaline builder salts, organic alkaterial is a mixture of sodium dodecylbenzene sulfonate line sequestrant builder salts and mixtures thereof. and Sodium tripolyphosphate- 2. The composition of claim 1 wherein the amine ox- References Clted ide is N,N-dimethyl-3-dodecoxy-Z-hydroxypropylamine UNITED STATES PATENTS 5 2,999,068 9/1961 Pilcher et al. 202-137 3. The composition of claim 2 wherein the said ma- 3,001,945 9/1961 Drew et terial is sodium dodecyl-benzene sulfonate.

4. The composition of claim 2 wherein the said ma- MAYER W T, Prima y xa n terial is sodium tn'polyphosphate. 10 U5, C1, X R

5. The composition of claim 2 wherein the said ma- 252-152; 260-584 

